Sanders Marble, senior historian of the United States Army’s Office of Medical History, presents a collection of essays related to the problems of substandard manpower as defined at different times in Western militaries over the modern era. Accordingly normally rigorous peacetime entrance standards have established conditions for the exclusion of certain individuals on the basis of physical, intellectual, ethnic, and racial criteria. During conflict, however, such notions of exclusion and exceptionalism are modified to reflect the needs of the army relative to the specific crisis. Marble’s Scraping the Barrel: The Military Use of Substandard Manpower, 1860-1960 (Fordham University Press, 2012) examines eleven case studies related to so-called “substandard manpower,” offering a series of assessments on military force structure in wartime. in this interview, our host talks with Sanders Marble about the overall project and his specific essay on American forces in the twentieth century, “Below the Bar: The U.S. Army and Limited Service Manpower.” He also speaks briefly with sociologist Thomas Sticht about his contribution to the volume, a deep analysis of the Department of Defense’s much-maligned “Project 100,000” in the essay “Project 100,000 in the Vietnam War and Afterward.”